Usually in elevators the elevator car body is generally fitted inside an elevator car sling, which the elevator car sling is suspended by hoisting roping and fitted to travel along guide rails. The guide rails are formed by connecting successive guide rail members together such that joints are formed in the assembled guide rails. These joints and possible impreciseness in guide rail alignment causes vibrations to the elevator car body via the elevator car sling connected to the elevator car body. This means that ride comfort in the elevator suffers and noise increases, which is especially the case with high speed elevators. Ride comfort for high speed elevators is very much influenced by the interface between the elevator car and the sling.
Base isolation is a well-known principle in the construction industry and is usually used to protect buildings against earthquake. Sometimes it is even used in server rooms to protect computer equipment against earthquake. The principle is to use a relatively low frequency base so that ground movement has very little effect on the movement of the building. However this cannot be used as such in elevators because as a difference between elevators and buildings, buildings are not coupled at the top to the ground which is the case with elevators in which the elevator car body is fixed to the elevator car sling at the top of the elevator car body, and thus it is coupled to the rail also at the top.
In prior art depending on the load of the elevator car several springs are used for isolating the floor of an elevator car body from the elevator car sling. The top of the elevator car has to be additionally supported because a top fixing limits the movement of the elevator car in case of emergency braking and also it is needed for supporting the tilted elevator car due to doors, toe guard and inner decoration.